Field of Invention
The present invention relates to a dynamic damper device, particularly to a dynamic damper device mounted to an output-side member of a torque converter.
Background Information
A torque converter is equipped with a lock-up device to reduce fuel consumption. The lock-up device is disposed between a front cover and a turbine, and is configured to mechanically couple the front cover and the turbine to directly transmit a torque therebetween.
In general, the lock-up device includes a piston and a damper mechanism. The piston is pressed onto the front cover by the action of hydraulic pressure, and a torque is transmitted to the piston from the front cover. On the other hand, the damper mechanism includes a plurality of torsion springs, and the piston and an output-side member coupled to the turbine are elastically coupled by the plural torsion springs. In the lock-up device as described above, the torque transmitted to the piston is transmitted to the output-side member through the plural torsion springs, and is further transmitted to the turbine.
Incidentally, Japanese Laid-open Patent Application Publication No. 2009-293671 describes a lock-up device in which an inertia member is mounted to the output-side member to inhibit variation in engine rotation. In the lock-up device described in Japanese Laid-open Patent Application Publication No. 2009-293671, the inertia member is mounted to the output member fixed to the turbine to be rotatable relative thereto. Furthermore, torsion springs are mounted as elastic members between the output-side member and the inertia member.
In the lock-up device of Japanese Laid-open Patent Application Publication No. 2009-293671, the inertia member is coupled to the output member through the torsion springs. Therefore, the inertia member and the torsion springs function as a dynamic damper, and these components attenuate variation in rotational speed of the output-side member (turbine).